There's a lot to unpack here. Western Europe took in more immigrants than the United States did last year, by numbers and percentage. You could make an argument that illegal immigration tips that towards the US, but I don't think that's true.
> relatively ethnically homogeneous societies, which is what you see in Europe
So, this one. It's always hard to say because European countries don't measure "race" in the way that the US does. The concept of knocking on peoples' doors and asking them what race they are is absurd to the average European. It's funny because this discussion kind of lays clear that the concept is poorly defined and the American conception of "race" isn't really true. Other than the phenotypical differences between east asians, blacks, and red-haired whites; there is so much variance amongst the rest that there is hardly anything you could call a "race" if you mean a demonstrably different genetic phenotype.
If you think that the Netherlands is a white ethno-state, then I'm not sure what to tell you. It's not, not even close. Germany brought a million Syrians into its borders a few years ago. The only part of Europe that doesn't have large-scale immigration and white ethno-states is eastern Europe. Even Scandinavia has pretty large-scale immigration at this point, except for Finland (also not a part of Scandinavia really, but important to clarify). They need the people. If you've ever been to Oslo, it is very obvious why. The place is empty.